1. Field of the Invention
The present invention relates to a biosensor with a silicon nanowire and a method of manufacturing the same, and more particularly, to a biosensor with a silicon nanowire including a defect region formed by irradiation of an electron beam, and a method of manufacturing the same.
This work was supported by the IT R&D program of MIC/IITA. [2006-S-007-02, Ubiquitous Health Monitoring Module and System Development].
2. Discussion of Related Art
In general, a biosensor is a device for measuring variation depending on biochemical, optical, thermal, or electrical reaction. The latest tendency in research has been toward research on electrochemical biosensors.
The electrochemical biosensor senses variations of conductivity generated from reactions between a target molecule and a probe molecule in a silicon nanowire to detect a specific biomaterial.
FIG. 1 illustrates a structure of a conventional biosensor.
Referring to FIG. 1, the conventional biosensor includes a silicon substrate 100, source and drain regions 110 and 120 formed on the silicon substrate 100, and an insulating layer 130 disposed between the source and drain regions 110 and 120, according to a basic structure of a field effect transistor (FET). A pre-manufactured silicon nanowire 140 is dispersed on the source and drain regions 110 and 120, and the insulating layer 130. Then, after finding the silicon nanowire that is capable of connecting the source and drain regions 110 and 120 by means of an electron microscope, metal electrodes 150 are patterned to make the silicon nanowire 140 in contact with the source and drain regions 110 and 120.
At this time, in order to improve performance of the transistor, the doping concentration of the silicon nanowire must be increased to improve electron mobility, thereby lowering contact resistance against the metal electrodes. On the other hand, in order to increase sensitivity of the biosensor, the doping concentration of the silicon nanowire must be lowered to decrease electron mobility such that the silicon nanowire is operated at a low current. This is because the difference in surface charge when a biomaterial adheres to a nanowire surface can be more effectively detected when a current flowing through the silicon nanowire is lowered.
Therefore, in order to improve performance and sensitivity of the biosensor manufactured on the basis of the transistor structure, it is necessary to provide a biosensor manufacturing method capable of lowering contact resistance between the silicon nanowire and the metal electrodes and lowering current flowing through the silicon nanowire.